Лекция Неотл ЭХОКГ / Emergency Echocardiography

168 APPENDIX F

TABLE F.1. (continued)

aLinear dimensions can be obtained by either M mode or M-mode guided two-dimensional measurements, depending on image quality and orientation. Because of technological advances, the use of the actual blood-tissue interface rather than the original leading edge-to leading edge requirement is suggested now for linear measurements

bFor clinical use, some measurements need indexing to body surface area as emphasized above. This may be critical especially for borderline values and individuals with body size significantly below or above the average RVOT right ventricular outflow tract, LVOT left ventricular outflow tract, LA left atrium, RV right ventricular, LVDd left ventricular diastolic dysfunction, IVSd interventricular septal wall thickness in diastole, LVPWd left ventricular posterior wall dimensions, BSA body surface area

References

1. Lang RM, Bierig M, Devereux RB, et al. Recommendations for chamber quantification: a report from the American Society of Echocardiography’s Guidelines and Standards Committee and the Chamber Quantification Writing Group, developed in conjunction with the European Association of Echocardiography, a branch of the European Society of Cardiology. J Am Soc Echocardiogr 2005;18:1440–1463.

2. http://www.bsecho.org/Guidelines%20for%20Chamber%20Quantification.pdf

FIG. G.1. Transesophageal echocardiography (TEE) imaging of a normally functioning St. Jude valve in mitral position. a Diastolic frame showing

APPENDIX G 171

FIG. G.2. Transesophageal echocardiography (TEE) findings in a patient with a bileaflet mechanical valve in mitral position, admitted with cardiac failure and hemolytic anemia. A high velocity, turbulent regurgitant jet is seen, originating at the suture line level consistent with significant paravalvular regurgitation.

•Jets origin is “within the valve” as opposed to paravalvular leaks (Fig. G.2)

•The appearance of one or multiple jets with a pattern that fits the description for a particular kind of valve

°Bileaflet valves may have up to three to four jets at the periphery of the valve (Fig. G.1c)

•Overall severity is no more than mild

PRESSURE GRADIENTS, PRESSURE HALF-TIMES AND EFFECTIVE AREAS

Pressure gradients across prosthetic valves are obtained with Doppler interrogation as for native valves and should be interpreted against published normal values.1 Increased gradients may

FIG. G.1. (continued) symmetrical and almost parallel leaflets ensuring full opening of the valve. b Systolic frame confirming symmetrical and simultaneous closure of the leaflets. c Color-Doppler systolic frame showing three short, low-velocity jets, typical for this valve.

172 APPENDIX G

suggest obstruction, but some caveats are to be observed before making the diagnosis of stuck valve, especially if this is an incidental finding in an asymptomatic patient:

•Gradients may be high with small diameter valves if valvepatient mismatch exists. Ideally, a study performed in steady conditions after surgery (but not immediately postoperatively) should be available for comparison.

•Gradients may significantly increase with high output states such as acute febrile disease, dialysis patients with shunts, and hyperthyroidism. Also, mitral gradients can increase markedly with high heart rates.

•A disproportionately high-peak gradient with a minimally elevated mean gradient in a prosthetic valve in mitral position is highly suggestive of regurgitation rather than obstruction.

Dimensionless Velocity Index (DVI). Peak velocities and gradients are highly dependent on flow and their use as isolated findings to diagnose valve obstruction may be limited. With changing flows, aortic valvular and subvalvular velocities are expected to maintain their relative ratio. The left ventricular outflow tract (LVOT) peak velocity/aortic valve peak velocity ratio is referred to as the DVI. A DVI 0.25–0.3 suggests valvular stenosis.

Effective areas for prosthetic aortic valves can be calculated using continuity equation and compared with published references. For prosthetic valves in mitral position a prolonged pressure half-time value can indicate obstruction. The pressure half-time (P1/2T) has not been thoroughly validated for prosthetic valves areas and its value should be reported as such, but resulting areas are frequently reported for practical reasons.

REFERENCE VALUES

There is a multitude of data on normal Doppler values for prosthetic valves, however, they represent a mixture of in-vitro and in-vivo, manufacturer-provided, clinical and experimental studies, some of which use only velocities or only gradients and report mean and standard deviation (SD) only or range of values as well. Also, areas and gradients vary greatly with valve size and flow state at the time of the study. As such, it is difficult to summarize the existent infor- mation.1-2 A compilation of orientative range of accepted maximal values is provided below, to “flag” a possible pathology and to be used with detailed published data on specific prosthetic valves.

Low valvular areas and gradients at the upper limit of the range are associated with small size valves and do not necessarily mean that the valve is malfunctioning. Some valves, such as

APPENDIX G 173

TABLE G.1. Acceptable values for biological and mechanic porsthetic valves over available sizes range.

AORTIC POSITION

AVA: aortic valve area, P ½ T: pressure half-times

the ball-cage Starr-Edwards have gradients at the upper limit of normal range.

SUSPECT REGURGITATION IF FINDING:

•High peak gradient with minimally increased mean gradient and no other evidence of obstruction

•High velocity, turbulent regurgitant jets, not typical for the valve (Fig. F.2)

SUSPECT STENOSIS IF FINDING:

•Both peak and mean gradient are elevated above normal range

•For aortic position

°AVA < 1 cm2 (by continuity equation)

°DVI < 0.3

•For mitral position

°Pressure half-time > 200 ms

Use reference values and previous studies for comparison (Table G.1).

References

1. Rosenhek, R, Binder T, Maurer G, Baumgartner H et al. Normal values for Doppler echocardiographic assessment of heart valve prostheses. J Am Soc Echocardiogr. 2003;16(11):1116–1127.

2. Rimington H, Chambers JMD. Echocardiography: A Practical Guide for Reporting. 2nd ed. London: Informa Healthcare; 2007. vi, 148 pp.

176 APPENDIX H

2.Lang RM, Bierig M, Devereux RB, et al. Recommendations for chamber quantification: a report from the American Society of Echocardiography’s Guidelines and Standards Committee and the Chamber Quantification Writing Group, developed in conjunction with the European Association of Echocardiography, a branch of the European Society of Cardiology. J Am Soc Echocardiogr 2005;18:1440–1463.

3.Cheitlin MD, Armstrong WF, Aurigemma GP, et al. ACC/AHA/ASE 2003 guideline update for the clinical application of echocardiography: summary article: a report of the American College of Cardiology/ American Heart Association Task Force on Practice Guidelines (ACC/ AHA/ASE Committee to Update the 1997 Guidelines for the Clinical Application of Echocardiography). Circulation 2003;108:1146–1162.

4.Douglas PS, Khandheria B, Stainback RF, et al. ACCF/ASE/ACEP/ ASNC/SCAI/SCCT/SCMR 2007 appropriateness criteria for transthoracic and transesophageal echocardiography: a report of the American College of Cardiology Foundation Quality Strategic Directions Committee Appropriateness Criteria Working Group, American Society of Echocardiography, American College of Emergency Physicians, American Society of Nuclear Cardiology, Society for Cardiovascular Angiography and Interventions, Society of Cardiovascular Computed Tomography, and the Society for Cardiovascular Magnetic Resonance. Endorsed by the American College of Chest Physicians and the Society of Critical Care Medicine. J Am Soc Echocardiogr 2007;20:787–805.

5.Lester SJ, Tajik AJ, Nishimura RA, Oh JK, Khandheria BK, Seward JB. Unlocking the mysteries of diastolic function: deciphering the Rosetta Stone 10 years later. J Am Coll Cardiol 2008;51:679–689.

6.Quinones MA, Otto CM, Stoddard M, Waggoner A, Zoghbi WA. Recommendations for quantification of Doppler echocardiography: a report from the Doppler Quantification Task Force of the Nomenclature and Standards Committee of the American Society of Echocardiography. J Am Soc Echocardiogr 2002;15:167–184.

7.Shanewise JS, Cheung AT, Aronson S, et al. ASE/SCA guidelines for performing a comprehensive intraoperative multiplane transesophageal echocardiography examination: recommendations of the American Society of Echocardiography Council for Intraoperative Echocardiography and the Society of Cardiovascular Anesthesiologists Task Force for Certification in Perioperative Transesophageal Echocardiography. J Am Soc Echocardiogr 1999;12:884–900.

8.Vahanian A, Baumgartner H, Bax J, et al. Guidelines on the management of valvular heart disease: The Task Force on the Management of Valvular Heart Disease of the European Society of Cardiology. Eur Heart J 2007;28:230–268.

9.Zoghbi WA, Enriquez-Sarano M, Foster E, et al. Recommendations for evaluation of the severity of native valvular regurgitation with twodimensional and Doppler echocardiography. J Am Soc Echocardiogr 2003;16:777–802.

10.British Society of Echocardiography 2005: Minimum Dataset for TTE (on BSE website)

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Websites

Organizations

1. American Society of Echocardiography (ASE). www.asecho.org 2. British Society of Echocardiography (BSE).www.bsecho.org 3. European Association of Echocardiography (EAE). www.escar-

dio.org/communities/EAE/pages/welcome.aspx

Free Domain Webcasts, Images, Guides

1. ASE University. www.aseuniversity.org

2. Echo by Web. www.echobyweb.com

3. Echo in Context. www.echoincontext.mc.duke.edu

4. E-chocardiography Journal. www.2.umdnj.edu/~shindler/ index.htm